The present invention generally relates to a method of utilizing spent silica-alumina catalyst (or F.C.C. catalyst) as an absorbent for waste liquid material. More particularly, the present invention relates to a method whereby spent silica-alumina catalyst is utilized so as to absorb waste material which can either be liquids or a mixture of liquids and solids so that when the spent catalyst is brought into contact with such waste material, a non-flowable, substantially solid mass having the waste material absorbed therein will result. The method of the present invention finds particular utility in the removal of hazardous liquid spills.
The spent silica-alumina catalyst which is suitable for use in the practice of the novel method of the present invention is typically that catalyst which is discarded as waste after it has served as a catalyst for the fluid-bed cracking of petroleum. Such silica-alumina catalyst are believed to be in and of themselves well known to those in this art and, thus, detailed description thereof need not be supplied herein. Conventionally, users of spent silica-alumina catalyst have a problem of disposing of such spent catalyst after it has served its intended functions as a catalyst for the fluid-bed cracking of petroleum.
There have been proposals in the past, however to utilize such spent silica-alumina catalyst for use as a sewer waste water treating agent as exemplied by U.S. Pat. No. 3,960,760 to Sanga et al, the entire disclosure which is expressly incorporated herein to by reference. In accordance with Sanga et al, prior to its use as a waste water treating agent, the silica-alumina catalyst must first be contacted with an aqueous solution of sodium hydroxide at a temperature range of between 70.degree. C. to 105.degree. C. to thereby produce a powder useful for removing ammonium ions and heavy metal ions from waste water. According to Sanga et al therefore, it is only after such treatment that waste or spent silica-alumina cracking catalyst will be useful to treat sewer waste water.
The process of the present invention seeks just the opposite effect in that it has surprisingly been found that raw or untreated spent silica-alumina cracking catalyst can be contacted with waste material so as to form a non-flowable, substantially solid mass. Oftentimes, use of the spent silica-alumina catalyst will result in a lower relative volume of the spent catalyst being required to absorb a unit volume of waste material when compared to popular absorbent material now conventionally utilized.
Reduced resulting volume of absorbants is significant when consideration is given to the cost factors involved in disposing of environmental waste such as hazardous chemicals, petroleum products, oil or the like in a regulated landfill. Typically, landfill operators charge their customers by a unit volume (typically a cubic yard) of matter that is to be deposited in a landfill. Thus, in accordance with the present invention, there is provided a method whereby less resulting volume of absorbent is needed to absorb a unit volume of waste material. This will necessarily translate into less overall disposal costs since more waste material can be deposited in a landfill per unit cost.
Furthermore, since the spent silica-alumina catalyst is typically a waste material from the viewpoint of the petroleum cracking operators, the spent catalyst can be obtained for relatively minimal cost when compared to costs of other conventional absorbents.
These and other advantages of the present invention will become more clear to the reader after detailed consideration is given to the description of the preferred exemplary embodiments thereof which follow.